Known dietetic nutrient compositions for patients with kidney insufficiency (Green List, 1989, Alendorf: Edition Cantor, Numbers 12005, 14004) comprise an albumin component in the form of oligopeptides and have a total energy content of about 100-130 kcal/100 ml and a phosphorus content of about 10-13 mg/g protein. An albumin component in the form of oligopeptides is disadvantageous in that, owing to the destruction of the structure of the protein due to the procurement of the oligopeptide, there is no longer any meaningful possibility for kitchen processability. Additionally, the sensory qualities of the compositions differ considerably from those of cow's milk. For example, the very bad taste of oligopeptides significantly impairs patient acceptance, particularly when sustained use is required. Further, the total energy content of the compositions appears to be relatively small while the phosphate content is at the upper limit of desirability.
WO 88/02219 discloses a phosphorous-reducing milk having a lower phosphate content which is within the upper limit of desirability for patients with kidney insufficiency. The albumin component of the milk is based on casein proteins which are obtained by precipitation with lactic acid from skim milk. Phosphoric acid is precipitated by means of calcium from the remaining whey, after which the casein is readded. However, phosphorus which, at the moment of precipitation, is still trapped in casein proteins remains in the product whereby the desirable low phosphorus values cannot be attained using these casein proteins. Additionally, lactic acid treatment can, at least in terms of tendencies, lead to structural changes that could make kitchen processing of the milk more difficult. Further, the overwhelming portion of the protein in the milk comes from casein and therefore disadvantageously has a relatively small content of essential amino acids that otherwise would have a very high valence for the patient. Finally, the process involved in obtaining casein proteins by means of precipitation and their reconstitution results in a product which generally can be sold commercially only in the liquid form.
From the Green List 1989, Aulendorf, Edition Cantor, No. 01005, an albumin-poor beverage produced from whey components is known. The beverage is designed for amino acid metabolism disorders that lead to the formation of toxic metabolism products in the patient. The beverage product has an increased phosphorous content of more than 38 mg/g protein and therefore is prohibited for administration to patients with kidney insufficiency. Additionally, the total energy content of the beverage is unacceptably low for patients with kidney insufficiency.
Thus, a need exists for a dietetic nutrient which is suitable for consumption by patients with kidney insufficiency and which overcomes the disadvantages of these known compositions.